Decreased Lysosomal Polarity during Acute Alcoholic Liver Injury Revealed by a Near-Infrared Fluorescent Probe.

Acute alcoholic liver injury (AALI) has become one of the main causes of chronic liver disease worldwide, and developing rapid, highly sensitive methods for AALI detection is urgently needed. AALI is closely associated with lysosomal damage; however, as an important microenvironmental indicator reflecting lysosomal status, the changes in lysosomal polarity during AALI are still unclear. Herein, we report a near-infrared fluorescent probe, Lyso-BF, to target lysosomes to unveil the lysosomal polarity changes during AALI. The probe uses a coumarin-conjugated dioxaborine as the fluorescent group and a morpholine unit as the targeting group for lysosomes. Lyso-BF is sensitive to polarity and can locate lysosomes to detect lysosomal polarity changes in living cells. On this basis, an AALI mouse model was established for imaging. The results showed that Lyso-BF can quickly image AALI, and the liver of AALI mice displays significantly brighter fluorescence signals than normal liver tissue, indicating a decrease in lysosomal polarity during AALI. This work not only demonstrates that lysosomal polarity is an effective indicator for rapidly detecting AALI but also provides an effective molecular probe for imaging and studying AALI.